Machine tool



Dec. 2, 1941. l J. E. LOVELY 2,264,804

lvmcmmf: T001J Filed Jan. 4, 1940 6 sheets-sheet 2 ff J2 i www J. E. LOVELY MACHINE TOOL Dec. 2, 1941.

Filed'Jan. 4, 1940 6 Sheets-Sheet 3 J. E. LOVELY MACHINE TOOL Dec. 2, 1941.

6 Sheets-Sheet 4 Filed Jan. 4, 1940 J. E. LOVELY MACHINE TOOL Dec. 2, 1941.

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Patented Dec. 2, 1941 MACHINE TOOL John E. Lovely, Springeld, vt., assigner to Jones a Lamson Machine Company, Springfield, Vt., a corporation oi' Vermont Application :mum 4, 1940, semi No.s1z,41z A This invention relates to machine tools and has for an object to provide for various controls possible with the machine tool illustrated in the Lovely and Knights Patents No. 2,065,816 granted December 29, 1936, but with a much simplified mechanism and which also makes possible other controls not possible in the patented machine.

A further object is to provide for power jogging actuation of the cam drums of the machine under the oontro1 of the operator which faouitate seiting up of the machine for a work cycle.

'To these ends and with further advantages, as will. more fully appear, the controlling cam drums are individually motor driven at fast speed. thus avoiding the necessity of the fast speed mechanical drive connections between the cam drums shown in the patent and making possible electric switch control both automatic and manual as may be desired.

For a more complete understanding of this invention reference may be had to the accompanying drawings in which Figure l is a Yfront elevation of a machine tool embodying the invention.

Figures 2 and 3 are left and right hand elevations, respectively, of the same.

Figure 4 is a rear elevation of the machine.

Figure 5 is a sectional view on line B-B of Figure 4.

Figure 6 is a detail section on line 8-8 of Figure 2.

Figure 7 is a fragmentary exploded perspective view of certain clutch parts shown in Figure 6.

Figure 8 is a diagrammatic view of the driving 'mechanism Figure 9 is an electrical wiring diagram showing the various controls.`

'I'he machine shown is of the general construction illustrated in the Lovely et al. patent to which reference has already been made. It comprises a bed having a headstock 2 and a turret carriage 3 which is movable on ways 4 toward and from the headstock. This machine is of the Fay type having the front and rear tool bars 5 and 6, respectively. The tool bar 5 supports the front' tool carriage 1 and the back tool bar 6 supports the back tool-carrying arm 3. The angular position of the carriage 1 may be controlled by the former cam 8 upon which rides the follower I of the tool carriage 1. This former cam is angularly adjustable as on the adjusting screws and is supported on a carriage l2 arranged for reciprocating motion and controlled by cams (not shown) on a headstock cam drum I4 throughla slide l5 and a link connection I8 with the slide l2. Similarly the arm 3 has its angular position controlled by a back former cam 20 on which rides a follower 2| carried bythe rear lower end of the arm 8.

Certain other controls of the machine are effected by cams (not shown) on a second cam drum 25 which is mounted within the base I beneath the turret slide. Details of the various l0 controls from the cam drums may be as shown in the Lovely and Knights patent. and per se, form no part of the present invention.

As also shown in Figure 6 of that patent, the controlling cam drums are in axial alinement with each other but are entirely independent in their mounting and drive.

Referring to Figure 8 of the drawings, at 30 is indicated a main motor which is connected to drive the work spindle 3|. being shown as belt connected to the pulley 32 which corresponds to the driving pulley 20 of the `Lovely and Knights patent. This pulley 32 is secured to a shaft 33 and there is a train of gearing shown. as a whole at 34 between the shaft 33 and the work spindle 3|. This train of gearing may be and is shown as that illustrated in Figure 32 of the Lovely and Knights patent. At 35 is shown a brake pulley connected to the drive mechanism in the same manner that the brake pulley 222 of the Lovely and Knights patent is connected. The various control handles 38, 31 and 3 8 correspond exactly with the handles 36, 43 and 66, respectively, of the Lovely and Knights patent, except that the handle 36 hasan additional. connection through the brake actuating linkage 48 with a rock arm l4| having an actuating cam 42 for closing a nor.. mally open two pole switch Si, the purpose of which will later more fully appear.

As in the patented construction, the low speed 40 drive for the cam drums' I4 and 25 is derived from the rotation of the work spindle 3 the drive being taken from the bevel gear on the work spindle to a bevel gear 46 carried by a shaft 41.

- From the shaft 41 the drive is identical to that 45 shown in the patent, through the change gear mechanism indicated as a' whole at 43 and the clutch 49 to the worm shaft 50 which drives the drum |4.\` The clutch-shifting mechanism for the low and high speed drive of this drum |4 50 lmay be substantially identical with that for driving the drum IIB of the patent, but the high speed drive for the worm shaft 30, instead of being through a gear train from the drive forA I the shaft 33. is derived from a high speed `motor 52. the yarmature of which is connected through 2 l accesos ,l

` rotation of one cam drum serving to start the the intermeshing bevel gears 53 and 54 with the clutch element 55. The details of thesedrives are shown in Figures 6 and '1. The clutch elements 49 and 550 are slidable on splined portions of the shaft 50 and have clutch lugs 55| which may be -moved 'into or out of driven relation to lugs 552 on the high and low speed driving clutch element 55 and 552, respectively, byv shift levers 554 and 555 connected by a. link 555 which is shifted by cam elements such as 551 engaging a follower 558 on a connecting lever 555 engaged by a load and fire cam 550 to insure complete throw in each direction. 'Ihe selection and change from one to the otherv of the high and low speed drive for each cam mechanism is thus eifected by cams on the same mechanism. Also rotatable with the cam drum I4 is the supplemental cam drum 55 similar to the cam drum 500 of the patent. A

The slow speed drive for the drum 25 is Vproduced in the same manner as shown in the patent, through the long shaft 50, and the change gear mechanism 5 to the right hand drum worm shaft 52. The supplemental cam drum 55 is also driven from the cam drum 25 in the same manner as the supplemental cam drum 505 of the patent.

The high speed drive of the right hand cam drum 25 and the supplemental drum 55, instead of being derived from the main shaft 33, as in the patent, is derived from Va second high speed motor 58 which drives the clutch element 59, which may be made eifective to drive the cam drum by shifting the clutch element into engagement therewith which disconnects the low speed drive mechanism of the clutch 1I. The details of this drive may be the same as shown in Figures 6 and 7. The turret mechanism may also be driven in the same manner as shown in the patent from a splined shaft corresponding to the shaft 451 of the patent.

'Ihe various cam controls derived from the cam drums 4 and 25 m-ay be identical to those from the drums |I0 and of the patent, as may also be the controls from the high and low speed drives to the supplementary cam drums. 55 and 55 corresponding to the supplemental cam drums 50 and 605, respectively, of the patent.

'Ihe mechanical controls for the high speed drive shown in the patent, however, are eliminated and in piace thereof are positioned electrical controls, certain being actuated by the supplementary cam drums and certain being operator-controlled and carried by a control board 80, which as shown in Figure l, may be positioned on the forward face of the headstock 2 in convenient position for the operator.

Theautomatic controls comprise switch throwing lugs as 8| removably secured to end face members 82 and 83 of the supplementary cam drums 55 and 55, respectively. The vswitches actuated by the elements 8| on the left hand supplementary cam drum 55 are the stop switch Si for the left hand drum fast motion motor. the normally open starting switch Sa for the right hand fast motion motor 55. and the normally closed starter lever release switch Se. The switches actuated by the lugs 5| on thesupplementary drum 55 are vthe normally closed starter lever release switch Ss, the normally open starting switch Se for the left hand fast motion motor 52, and the -stop switch Sv for the right hand fast motion motor 52. It will be noted that there is an intercontrol between the cam mechanism, 75

Iso that they may be jogged."

rotation of the other before it stops itself.

0n the switch board 00 are positioned the following switches: the main motor push button starting switch A, the master stop push button switch B, the Jog selectors JS; and JS: lfor the left and right hand fast motion motors 52 and l5, respectively, Jog push buttons D1 and Da for these same fast motion motors, respectively, the lead selector switches LS1 and LSrfor these same motors, respectively, the restart push button E, the start push buttons Fi and Fn for the left and right hand fast motion motors, respectively.

Beside these controls on the panel 00 and the automatic controls actuated by the contacts 0| on the supplementary cam drums, there are other controls as follows: A starter lever contact switch S1, a magnetic starter M for the main motor 30, and magnetic motor starters K and L for the left and right hand fast motion motors 52 and 58, respectively, and four control relays CB1, CRn, CR: and CRA.

'I'he wiring `diagram of these various controls is shown in Figure 9. The motors 3 0, 52 and 55 are shown as of a three phase type, deriving their energy from the power lines |00, |0| and |02. The magnetic'starter for each of these motors comprises the closing coil |03, which, be-

sides closing the corresponding three pole switch |04, also closes a holding circuit switch |05, |45, or 200 and the coil |03 is also connected to the overload circuit breaker |08. The starter push button A is connected through the lead |01 with the power line |02 and also through the leads |01 and I 05 with the holding switch |05 for the motor 30. The opposite side of the switch A is connected through the leads |09 and ||0 with the opposite Side of the holding switch |05. It is also connected through the normally closed stop push button B through the lead and the overload switch |05 with the magnet coil |02 and back through the lead ||2 to line wire |0I. Thus when the push button A is closed, the main motor is started into operation, and the closing of the switch |05 holds the Amagnetic switch M- closed so that the main motor 30 remains connected even on release of the starter push button A, but may be stopped by opening the stop push button at B. The main motor thus being running, the normally opened switch Si yis closed by 'moving the starter lever 35 to running position (see Figure 8), this movement of the lever 30 moving the switch actuator 42 into switch-closing position. It is only when the main motor is running that the fast motion motors 52 and 58 may be actuated, and stopping of the motor by a depression of the stop push butv ton B will also cause the fast motion motors 52 and 55 to stop, if they happen to be running at that time.

'I'he closing of the switch S1 conditions the controls for operation of the fast motion motors 52 and 55, either in normal running relation, or

"Jogging comprises a driverof the motor so long as a Jog control push button is depressed, removal of pressure immediately causing this motor to stop. In x the normal running control the motor is out of control of the jog push button. The jog selector switch for the left hand motor 52 is shown at JB; and may be moved selectivelyinto contact'with either the running contact H 3 or the logging contact I I4. Similarly the `log selector for the motor 5,0, JSz, may be moved selectively into engagement with the running contact I5 or the jogging contact H5. The Jogging contact ||4 is con'-` lback to the power line nected through the lead ||1 with the normally open jog push button D1, and through this and the lead ||8 to the lead |09. The switch JSr is connected through the lead ||9 withthe overload relay |06 for the left hand motor 52, its switch-closing'coil |03, and through the lead |20 to the line wire lill, so that when the Jogging switch JSr is in jog position and the push button D1 is depressed, the magnetic switch K is closed, so that the left hand motor 52 is driven. This condition persists so long as the Jog switch D1 is closed, but immediatelyuponrelease of it, the motor 52 stops. f

Similarly the depression of the push button D: when the jog selector JSn engages the contact M6, will cause jogging rotation of the right hand push button Dn, the 'contact ||6, the Jog selector switch, the lead |2|, the right hand motor overload relay, its closing magnet |03, and back through the lead |22 to the power line |0| When the .10g selector switches JSi and JS: are

in their running position in engagement with the closed switch Sz. the lead |24, the normally closedswitch Ss, the lead |25, the magnet coil |26 of the relay CR4 and the lead. |21, back to the power line |0i.v This closes the normally open contacts |28 and |29 of the relay CRA. The closing of the contact |29 closes a circuit from the lead |21 through 4the latching coil I and the lead |30 to the lead |3| to the power line |02.

The energization of the coil I actuates a latch |32 (see Figures 4 and 8) which engages and holds the lever 4|, and consequently the starting lever 36 in running position. The starter lever 36 and its switch S1 thus remain closed until one or more of the switches S2 or Ss opens. The other contact |28 provides a connection through the lead |33 to the normally open switch |34 of the relay CRs. This lead |33 also connects through the leads |35 and |36 to normally closed switch E, leads |31 and |38 to the pole |39 o! LS1, and ifv this switch is closed, through the leads and |4| to the switch Sa and if this is closed, through the lead |42, the running contact ||3 of the jog switch J Si, through the lead I9, and the motor 68, the lead ||8 connecting through the Jog switch S4 is closed. Thelead |58 goes to the coil |60 of the relay CB1, the opposite side of which connects ,through the lead |62 to the power line |0|. Thus the maintaining circuit for the magnetic switch K through the switch |49 is continued through the lead |52 of the relay CRi, it the stop switch S4 is open, and continues through the switch S4; ii' it is closed, through thecontacts |62 and |64, thence through lead |42, the jog" selector contact ||3 and the overload relay |06 of the motor 52 to the line |0|.

While the left hand fast motor starter K is being closed and remains closed, 'as thus described, the right hand last motor starter L remains de-energized, the contacts of the lead selector LS: being open and the control relay CR: having not yet operated. This condition'prevails regardless of the control drum operated starter and stop switches Ss and S1. The lead selector overload relay |06 for the 'left hand motor 52, and

open and the selector switch LS1 is closed, connection is made through the second pole |43 of this switch, the lead |44, the normally closed con- VIf the switch Se is tact |45 of the relay CRn, the lead |46 to the lead |42, which carries back to the same jog contact ||3. Completion of this circuit causes the magnetic starter K to close and starts the left hand fast motion motor 52. Closing of the starter K causes the normally open auxiliary switch |48 to close, which establishes a maintaining circuit for the magnetic starting switch K through the leads |50, |5| and |33 through the normally open contacts |28, which is now closed, back to the line |3| and the power line |02. The opposite side of the switch |48 connects through the lead |52 and |53 through the normally closed contact |54 of the relay CRr to the lead |46. At this time the relay CR1 is deienergized if the stop switch S4 isbut is immediately energized through the open,

|51, leads |58 and |59, if the contacts |56 and switches thus control completely the sequence in which the fast motion motors start a new work cycle.

When the control relay CRi is energized, its normally closed contact |54 opensand its normally open .contact |65 closes. completing the connection from the line |35 through the contact |65, the lead |66, the coil |61 of the relay CRs, back to the lead |62, so that relay CRa` closes, thus opening the normally closed contact at |45 and closing three normally open contacts |34, v|10 and |1|.

The closing of the normally open contact |34 establishes a maintaining circuit for the coil |61 of the relay CRa from the line |0| through the lead |62, contact |34, lead |33, contact |28 of the relay CR4 and lead |3| to the line |02, which thus renders the relayCRa independent of all control devices except the relay CR4. The clos:- ing oi the normally open contact |10 of the'relay CRa establishes a by-pass circuit around one pole oi the lead selector LS1, since this closes connec-- tions from a lead |15 connecting to the lead |4| which connects through the lead |40. The closing of the relay contact 1| establishes a by-pass circuit around one pole |16 of the lead selector LS: since it connects from the lead |15 to the lead |11 and the lead |18. The closing of the relay CR: also opens a normally closed contact at |80, opening a by-pass circuit around the start switch Sa through the leads |8|, |62, whichconnect with the start switch Sa, through lead |83, and the lead |85, the pole |86 of the switch LSz, and the lead |84 which goes tothe other side of the4 start switch Sa. Thus the control relay CRa renders- S3, Si; Se, andA S1.A These lugs are so set that be- -f fore either of the cam drums actuating these switches stops, it insures the actuation of'the other, in order that the automatic control may be continuousthroughout the work cycle. At the end of the work cycle one or the other control drum operated starter release switches Sz' or Ss is mechanically opened thus causing the control relay CRA to become de-energized and open and remain open. This action, in turn, de-energizes the starter lever release solenoid I, causing the starter lever to return to the off position to which it-is urged by -the spring |90 (see Figure 4) and also de -energizes the magnetic coil circuits of the fast motion motor starters K and L and all the controli relays. Thus both fast motion motors 82 and 88 stopand the control relays are returned to the normal positions shown in the diagram of Figure 9. 'I'he main motor 80, however continues to run.

The next work cycle may then be started in the manner heretofore described with the lead selectors LS1 and L82 once more effective.

Ii the lead selectorLSa is closed to cause the right hand fast motion motor 88 to start the new cycle and the lead selector LS1 is open, the action is the same as above described, exceptvthat the control relayCRa will be closed through contacts of the`control relay CR: which corresponds in all its functions to the control relay CRi. Thus the closing of the leadselector LS: completes a circuit from the line through the magnetic coil |08 of the motor starter L. the overload relay |08, the lead |2|, the jog selector contact H8, lines |88, |82 and |8I, the normally closed-contact |80, lead |88, the switch arms |88, |18 and back to the line |88, line |81, the normally closed switch E, the leads |88 and |88 through the contact 28 of the closed relay CRi and the lead |8| to the line |02. y

The stop switch' S1 being closed, the coil |95 of the relay CRn is energized through the lead |82 coming from the line |0|, through the line |98, the stop switch Sn, line |88, jog selector running contact ||8, lead |2|, and the overload switch |08 and holding coil |08 of the right hand motor 88 which'starts the rotation of this motor. Closing of the starter L for this motor closes the normally open auxiliary switch 200 which establishes a maintaining circuit for the magnetic starting switch L through the leads |50, |5| and |88, through the normally open but now closed contact |28 back to the line |8| and the power line |02. The opposite side of the switch 200 connects through the leads 20| and 202, through the normally closed contact 208 of the relay CRn, through the lead 208, the leads |8| and |88, closed stop switch S1, coil |98 and lead |82 to line wire |0'|. The energization of the relay CR: through the coil |88 closes the normally open contact 208 which immediately energizes the coil |81 of the relay CRa from the lead |88, closing to the lead4 |8i, so that the relay CR: is then closed, whereas when the lead selector LS1 was first closed, this relay CR: remained open. rl'he action of the relay CRn is thus reversed from its former conditionl so that the right hand motor 88 now starts the cycle. I ,Y In the event of the stopping of the\machine before completion of the work cycle through voltage failure, tripping of an overload relay, or pressing of the master stop button, the cycle may be resumed by the following operations. First, the main motor 80 must be started by pressing the main motor start button A. 'Then 're-start push button E must be depressed and held depressed while the starting lever 88 is engaged, this operation closing the relay CRA and establishing a circuit vfrom line |02 through lead |8| through its normally open contact |28 through leads |88, |88, and normally open contacts 208 and 201 of the button E, lead |88, coil |81 of relay CRa, lead |82 to line |0|. Thus relay CRa closes rendering ineffective the existing setting of lead selectors LSi and LSa.

The parts are now so conditioned that by holding the restart button E depressed, either selected of the motors 82 or 88 may be started by depressning contacts ||8 or ||5 and the respective starter coils |08 of the motor starters K or L back to the line |0|.

From the foregoing description of an embodiment of this invention, it should be evident to vthose skilled in the art that various changes and modiiications might be made without departing from the spirit or scope of this invention as dened by the appended claims.

I claim:

1. A machine tool comprising work and tool holders, means including a pair of cam mechanisms for actuating and controlling said holders to perform a work cycle, means including a separate motor for driving each cam mechanism, switches controlled by cams of said mechanisms for controlling said motors, and operator-actuated switches for controlling said motors independently of said cam actuated switches.

2. A machine tool comprising work and tool holders. means including a pair of cam mechanisms for actuating and controlling said holders to perform a work cycle, means including a separate motor for driving each cam mechanism, switches controlled by cams of said mechanisms for controlling said motors, operator-actuated means for selecting one of said cam mechanisms to initiate the work cycle, and means for starting the operation of said machine tool.

3. A machine tool comprising work and tool holders, means including a pair of cam mechanisms for actuating and controlling said holders to perform a work cycle, means including a separate motor for driving each cam mechanism, switches controlled by cams of'said mechanisms for controlling said motors, operator-actuated `iog switches for each cam mechanisms, and means for selectively rendering the cam control switches operative or inoperative and said Jog switches ineiective or eifective, respectively, when actuated.

4. A machine tool comprising work and tool holders. means including a pair of mechanisms for actuating and controlling said holders to perform a workcyole, said mechanisms being arranged each to partly control the other, means including a separate motor for driving each mechanism, switch means for controlling said motors, and operator-actuated means for selecting one or the other of said mechanisms to initiate said work cycle.

5. A machine tool comprising work and tool holders, means including a pair of mechanisms for actuating and controlling said holders to perform a work cycle, one of said holders comprising a rotary spindle, means for driving said spindle, a drive for said mechanisms from said spindle, a motor for driving each mechanism, means operated by said mechanisms for selecting the drive from said spindle or from one or the other of said motors, and operator-actuable .means for starting operation of said machine tool.

prising a rotary spindle, means for driving said spindle, a low speed drive for said mechanisms from said spindle, a motor for driving each mechanism at a higher speed, means operated by said mechanisms for selecting the drive from said spindle or from one or the other oi' said motors, and operator-actuable means i'orstarting operation of said machine tool.

7. A machine tool comprisingwork and tool holders, means including va pair o! mechanisms i'or actuating and controlling said holders to perform a work cycle,.one oi said holders comprising a rotary spindle, means for driving said spindle, a drive for said mechanisms from said spindle, a motor for driving each mechanism, means operated by said mechanisms for selecting the drive from said spindle or from one or the other of said motors, operator-actuable means for selecting which of said mechanisms 1 5 shall start said work cycle, and operator-actuable means for starting the operation of said machine tool.

8. A machine tool comprising work and tool holders, means including a pair oi' mechanisms for actuating and controlling said holders to perform a work cycle, a motor for driving each of said mechanisms, other means for driving said mechanisms, said mechanisms including means for selecting either said motor drive or said other drive, interconnecting controls between said motors and mechanism 'for insuring operation of at least one of said mechanisms at all times during said work cycle,and operator-actuable means for selecting that motor which shall be operating at the start of said work cycle.

9. A machine tool comprising work and tool holders, one of said holders including a rotary spindle, means for rotating said spindle, means including a pair oi. mechanisms for actuating and controlling said holders to perform a work cycle, a plurality of means for actuating said mechanisms, one of said actuating means being in driven relation to said spindle-rotating means, other means for actuating each of said pair of mechanisms, said mechanisms including means for selecting and changing from one to the other of said actuating means, and means for preventing operation of said other actuating means unless said rotating means is in operation.

'10. A machine tool comprising work and tool holders, one of said holders including a rotary spindle, means for rotating said spindle, means including a pair of mechanisms for actuating and controlling said holders to perform a work cycle, a plurality of means for actuating said mechanisms, one of said actuating means being in driven relation to said spindle-rotating means, other means for actuating each of said pair of mechanisms, said mechanisms including lmeans for selecting and changing from one to the other` of said actuating means, means for, preventing operation of said other actuating means unless said rotating means is in operation, and opera tor-actuable means for selecting which ofsaid 6o mechanisms shall be ilrst actuated on the start of a work cycle.

11. A machine tool comprising work and tool holders, one of said holders including a rotary spindle, means for rotating said spindle, means 65 including a pair of mechanisms for actuating and controlling said holders to perform a work cycle, a plurality of means for actuating said mechanisms, one of said actuating means being in driven relation to said spindle-rotating means, 70 and another of said actuating means comprising a motor for driving each of said mechanisms.' said mechanisms including means for selecting and changing between its respective motor and said spindle-rotating driven means, each of said 75 mechanisms including means for stopping its own actuation, means insuring the actuation of one or the other of said mechanisms during a complete work cycle, and operator-actuable means for selecting the mechanism actuable at the beginning of each work cycle.

12. A machine tool comprising work and tool holders, one of said holders including a rotary spindle, means for rotating said spindle, means including a pair of mechanisms for actuating and controlling said holders to perform a work cycle, a plurality of means for actuating said mechanisms, one of said actuating means being in driven relation to said spindle-rotating means, and another of said actuating means comprising a motor for driving each of said mechanisms, said mechanisms including means for selecting and changing between its respective motor and said spindle-rotating driven means, each oi' said mechanisms including means for stopping its own actuation, means insuring the actuation oi' one or the .other of said mechanisms during a com.- plete work cycle, operator-actuable means for selecting the mechanism actuable at the beginning of each work cycle, and means preventing the operation of either of said mechanisms until after, said spindle-rotating means has been started. f

13. A machine tool comprising a rotary workholding spindle, means for rotating said spindle, tool holders, means for moving said tool holders relative to said spindle to cause tools on said tool holders to operate on work on said spindle in a predetermined work cycle, said means including apair of mechanisms, slow driving means for said mechanisms derived from said spindlerotating means, a motor for driving each of said mechanisms at a higher speed, said mechanisms including means for selecting and shifting from one of said driving means to the other driving means, and switches for controlling said motors including means for selecting the motor for operation at the start of each work `cycle and for starting one motor from the mechanisms driven by the other motor.

14, A machine tool comprising a rotary workholding spindle, means for rotating said spindle, tool holders, means for moving said tool holders relative to said spindle to cause tools on said tool 0 holders to operate on work on said spindle in a predetermined work cycle, said means including a pair oi' mechanisms, slow driving means for said mechanisms derived from said spindle-rotating means, a motor for driving each o1' said mechanisms at a higher speed, said mechanisms including means for selecting and shifting from one of said driving means to the other driving means, and switches for controlling said motors including means for selecting the motor for operation at the 'start of each work cycle, for starting one motor from the mechanism driven by the other motor, and for stoppingjeach motor from the mechanism driven thereby.

v 15. A machine tool comprising work and tool holders including a spindle, means for rotating said spindle, means for moving said holders relatively to perform a work cycle, said moving means including a pair of motors, means for starting and stopping the rotation of said'spindle, operator actuable means conditioned by said starting and stopping means to start the rotation of said spindle and means for causing rotationof one or the other of said motors only when said spindle is rotating.

16. A machine tool comprising work and tool aan,

holders including a spindle, means for rotating s said spindle, means for moving said holders relatively to perform a work cycle, said moving means including a pair of motors, means for starting and stopping the rotation of said spindleI means for causing rotation of one or the other of said motors only when said spindle is rotating, and means for selecting the motor operating at the start of a work cycle.

17. A machine tool comprising work and tool holders including a spindle, means for rotatingsaid spindle, means for moving said holders relatively to perform a work cycle, said moving means including a pair of motors,v means for starting and stopping the rotation of said spindle, means for causing rotation of one or the other of said motors Vonly when said spindle is rotating. means for selecting the motor operating at the start of a work cycle, means for stopping the machine tool, and means for re-starting the machine tool ouil of control of said selecting means.

18. A machine tool comprising work and tool holders including a rotary spindle. means for rtating said spindle. means including a plurality of motors vfor moving said holders relatively in a manner to perform a work cycle. means for starting the rotation of said spindle, a cycle control movable between an operative and an inoperative position'and biased to inoperative position, means eifective only when said spindle is rotating to retain said cycle control in operative position, and means eifective only when said cycle control is in operative positionn and said spindle is rotating to cause said holder moving means to operate to cause the performance of said work cycle,

19. .A machine tool comprising work and tool holders, means including mechanism for actuating and controlling said holders to perform a work cycle, one of said holders including a rotary shaft, a motor for rotating said shaft, a magnetic switch having a holding circuit for controlling said motor, means including a second motor for driving said mechanism, and an actuating circuit for controlling said second motor connected to said holding circuit to permit actuation of said second motor only when said holding cir cuit is closed.

JOHN E. LOVELY. 

